Cogging Torque Reduction in PMSM Motor by Using Proposed New Auxiliary Winding

Performing fast and accurate methods for modeling the electrical machines has been the subject of several studies and many authors proposed different procedures to attain this aim. Beside the accuracy, the speed of the method is of great concern. On the other hand, the capability of the method to be changed according to the need is another important issue. Finite Element method provides relatively accurate results but it is time consuming and changing the parameters, once the model designed is difficult to be done. Magnetic Equivalent Circuit method is rather a new concept to model the electrical machines. The most important feature of the method is its flexible accuracy which can be determined due to the user's desire. Another important characteristic is the capability of the method in changing parameters. In this paper, a permanent magnet synchronous motor is modeled using Magnetic Equivalent Circuit; the values of the magnetic flux density and magnetic field intensity are calculated. Afterward, the generated output torque is calculated using Maxwell Stress Tensor. The comparison between the results of the MEC model and the Finite Element Analysis reveals the sufficient accuracy of the proposed method. Finally, a new method is proposed for cogging torque minimization which is based on the torque pulsation originated from an auxiliary winding. The result shows a significant reduction in the amplitude of the cogging torque.